Camshafts are a permanent part of internal combustion engines. The camshaft has a (hollow) shaft, to which at least one cam is joined. Thermal joining methods are generally used to join the shaft and the cam. The connection of the shaft and of the cam is then ensured by means of a cam-side joining face, which is generally arranged in a cam bore, and a shaft-side joining face. The disadvantage of this is that the torque that can be transmitted via the camshaft is limited by the friction between the cam-side joining face and the shaft-side joining face.
DE 10 2009 060 352 A1 discloses a method for producing a camshaft for valve control in an internal combustion engine, comprising the steps: Aligning a plurality of disc-like cams, each having a central, round hole extending perpendicularly to a main cam plane, in such a manner that the holes of the cams arranged at an axial distance from each other align with each other. Supercooling a hollow shaft of round outer profile relative to the cam, the outer diameter of the supercooled hollow shaft being smaller and the outer diameter of the non-supercooled hollow shaft being greater than the inner diameter of the cam holes. Inserting the supercooled hollow shaft into the aligning cam holes. Effecting a temperature equalisation between the hollow shaft and the cams so that the hollow shaft and the cams are connected permanently to form a camshaft, the inner faces of the cam holes and/or the outer face of the hollow shaft having a rough pattern produced by laser ablation in the sections thereof that are surrounded by the cam holes when in the inserted state.